Device for lapping tapered mating surfaces of parts

ABSTRACT

Apparatus for lapping the tapered mating surfaces of parts, mainly bells and cups of blast furnace charging devices, and for ensuring accurate orientation in space of the parts during lapping and control of the load in the lapping contact zone. A cup is held rigidly on a stand while a bell in inserted into the cup with a thin layer of abrasive compound between the mating parts. The bell is then given a reciprocating-rotary lapping motion and occasionally, momentarily raised to slightly separate mating contact so as to ensure reorientation of abrasive grains, improve lapping efficiency and reduce lapped surface roughness.

United States Patent 1 Isaev et al. 1 Jan. 9, 1973 s41 DEVICE FOR LAPPING TA 1,237,189 8/1917 Finkbeiner .5 ..s1 29 ING FAC S 0F P RTS 1,460,724 7/1923 McGrath ..51/26 [75] Inventors: Alexei lllch lsaev, Moscow; Semen E M K H Albertovlch Pevzner, Kramatorsk 52:32 & 82: e y Donetskoi oblasti; Jury Semenovlch y Zemtsov, Orsk Orenburgskoi oblasti, all of U.S.S.R. 57 ABSTRACT Assigneel Klmfliltol'sky Nauchno'lssledovalfl Apparatus for lapping the tapered mating surfaces of y 1 proek-mo'tekhlfoloflichesky parts, mainly bells and cups of blast furnace charging smut f f Kramatorsk' devices, and for ensuring accurate orientation in space Donetsko' oblasu' of the parts during lapping and control of the load in [22] Filed: Nov. 18,1970 the lapping contact zone. A cup is held rigidly on a stand while a bell in inserted into the cup with a thin [21] Appl' 90518 layer of abrasive compound between the mating parts. The bell is then given a reciprocating-rotary lapping [52] US. Cl ..51/26 motion and occasionally, momentarily raised to Cl- ..t p t ti g t t so as ensure Fleld of Search 27, reorientation of abrasive g improve effi References Cited ciency and reduce lapped surface roughness.

UNITED STATES PATENTS 6 Claims, 3 Drawing Figures 3,385,007 5/1968 Anderson ..5l/29 DEVICE FOR LAPPING TAPERED MATING SURFACES OF PARTS The present invention relates to devices for lapping tapered mating surfaces of parts, mainly bells and cups of the blast furnace charging devices.

Known in the art are devices for joint lapping of the tapered mating parts, e.g. plug-type cocks. These devices comprise elements for setting and securing immovably one of the parts being lapped. The second lapped part is connected to a drive ensuring reciprocating-rotary motion and periodical separation of the surfaces of the parts being lapped.

The lapping process proceeds as follows. Before work, the mating surfaces of parts are coated with a layer of abrasive compound. The part connected with the drive begins to be reciprocated and simultaneously rotated. The surfaces being lapped are separated each time the direction of motion is reversed.

The known devices for joint lapping of parts are incapable of orienting the parts in space and relative to each other which distorts the geometrical dimensions of the mating surfaces of the parts being lapped, particularly of the parts with a large angle of taper and a low ratio of the cone element to its diameter.

Besides, pressure in the lapping zone depends on the weight of the part being rotated and cannot be adjusted which, in case of very heavy parts and small contact areas between the lapped surfaces, results in excessive increase of the unit loads, premature deterioration of the cutting abrasive grains and rapid discontinuance of cutting during lapping.

Thus, the known devices can be used for lapping only comparatively small parts with a relatively large area of contact between the surfaces being lapped. In this case the unit loads at the contact zone are not very heavy and the abrasive grains are not destroyed.

An object of our invention resides in providing a device which ensures accurate orientation in space of the parts being lapped, i.e., holding them in a coaxial position in the process of lapping, and adjusting the loads in the contact zone between the surfaces being lapped. Y

The present device for lapping the tapered mating surfaces of parts, mainly of the bells and cups of' the blast furnace charging devices, comprising elements for setting and fixing immovably one of the parts, a drive comprising a disc with radially protrudingelements for imparting a reciprocating-rotary motion to the second part with respect to the first part, and a drive for periodical separation of the parts beinglapped.

A characteristic feature of the device is that it comprises a vertical shaft, the disc with radially protruding elements secured on said vertical shaft and connected rigidly with the rotating part, and two synchronously operating reciprocating-rotary drives arranged diametrically opposite to the disc and interacting with its radial elements. I

The lower end of the vertical shaft in the present device is connected to a power drive for separating the parts being lapped, said drive serving as a support for said lower end of the shaft.

The power drive for separating the lapped surfaces of parts is made in the form of a hydraulic cylinder consisting of a casing, a piston with a rod, the latter being provided with a nut capable of moving along the rod 3x18.

In the present device the upper end of the vertical shaft is installed in a bearing which is located in a cross member mounted on two vertical columns.

The vertical columns are movable in a transverse direction with relation to the shaft to suit the dimensions of the parts being lapped.

In this specific embodiment of the device the reciprocating-rotary drive is made in the form of a hydraulic drive whose casing is secured rigidly to a guide while the piston rod is connected with a slide moving along the guide, said slide carrying two axlemounted spring-loaded cams which engage successively all the radial elements of said disc; mounted rigidly on the guide is a stop engaging one of the cams for lowering it by turning it around its axis at the end of the working stroke of the slide in one direction.

The use of the present device allows the parts to be held in a coaxial position within the entire process of lapping.This ensures unchanging conditions of contact between the parts being lapped and contributes to obtaining their correct geometrical shape.

Owing to adjustment of the axial position of the bell with relation to the cup, it becomes possible to reduce loads in the contact zone which wards off premature deterioration of the cutting grains, reduces the consumption of abrasive lapping materials and steps up the efficiency of the lapping procedure.

Transmission of the reciprocating-rotary motion to the part with the aid of two drives guarantees genera tion of a pure torque and eliminates lateral forces which tend to change the relative positions of the parts. This ensures a more accurate geometrical shapeof the surfaces being lapped.

The design of the device which provides for spreading apart the vertical columns in a transverse direction with relation to the shaft axis makes it possible to lap.

parts of different dimensions.

For a better understanding of the invention it will now be described in more detail'with reference to the drawings, in which: I

FIG. 1 is a diagrammatic view of a device for lapping tapered mating surfaces of parts, mainly bells and cups of blast furnace charging devices;

FIG. 2 is a'diagrammatic plan view of the device;

FIG. 3 is a section taken along line 3-3 of FIG. 1 (motion of slide and position of cams shown in dotted lines).

The present device is mounted on elements for setting and fixing immovably one of the parts, these elements made in the form of a stand bedl (FIGS. 1 and 2) on whichtwo vertical columns 2 are mounted with a provision for adjusting their position. The columns 2 support a cross member 3 so that the columns 2 and the cross member 3 form a gantry. Installed in the gantry openingsymmetrically with relation to the columns 2 and secured rigidly on the stand bed 1 is a cup 4 of the blast furnace charging device with a bell 5 inserted into Installed on the stand bed 1 is a drive 6 for separating the parts .4 and 5 being lapped, said drive consisting of a casing 7 accommodating a piston 8 with a rod 9 and a nut 10 screwed on the end of the rod 9 protruding from the casing 7.

The lower end of the vertical shaft 11 is inserted into the hole of the rod 9. The upper end of the shaft 11 is installed in the bearing located in the cross member 3.

The shaft 11 is coaxial with the tapered surfaces of the cup 4 and bell 5 being lapped.

Mounted with the aid of bearings 12, 13 onthe shaft 11 is an intermediate member 14in the form of a regular truncated tetrahedral pyramid which is connected by screws 15 and16 with the disc 17 provided with radially protruding elements 18, for example in the form of teeth. v

The toothed disc 17 is secured rigidly on the face of the hell 5 being lapped. The teeth 18 of the disc 17 are in mesh with two reciprocating-rotary drives 19 arranged diametrically opposite to the disc 17 and secured rigidly to the vertical columns 2.

The drive 19 comprises a hydraulic cylinder 20 (FIG. 3) consisting of a body 20a and a piston 21 with a rod 22.

The body 20a is rigidly fastened to a guide 23 while the rod 22 is connected with the slide 24 which carries two earns 26 and 27 mounted on axles 25. The earns 26 and 27 are held constantly in a vertical position by a spring 28.

The guide .23 carries a rigidly secured stop 29 made in the form of a strip and intended to lower the cam 27 atthe end of the working stroke of the slide 24 in one of the two directions.

The present device functions as follows.

For lapping the parts, the mating surfaces of the hell 5 (FIG. 1) and cup 4 set in the present device coaxially with the vertical shaft 11 are coated with a thin layer of abrasive compound.

The hell 5 connected with the rod 9 of the drive 6 is put in contact with the cup 4 by means of the intermediate member 14 and shaft 11 when the piston 8 with the rod godown.

The extreme lower position of the shaft 11 is limited by moving the nut 10 so that in this position of the shaft,part of the weight of the hell 5 and of the parts 14 and 17 of the. device connected with said hell would be taken by the nut 10, thereby ensuringnonnal conditions of lapping. 7

By reciprocating the piston 21 (FIG. 3) with the rod 22 and slide 24 of the drive 19, the bell 5 is set in reciprocating-rotary motion. This occurs because i when the slide 24 moves in one direction, the cams 26 of both drives l9 engage the teeth 18 0f the disc 17 which is fastened to the bell 5, putting it in rotation. When the slide '24-moves,-the cam 27 (shown by dotted lines) comes against the stop 29 and is lowered into the slide 24 overcoming the resistance of the spring 28 and the tooth 18 occupies position 18a.

Then thelslide 24 starts moving back and the ,cam 27,being released by the stop 29 and moving under-the tooth 18a will be moved by the spring 28 to the initial vertical position.

As the slide 24 continues its movement in the same direction, the cam. 26 (shown by-dotted lines) comes against the next tooth 18b of the disc 17, lowers into the slide 24 and moves under the tooth 18b while the cam 27, coming against the tooth 18b, turns the hell 5, transmitting the rotary motion in the opposite direction through the disc 17 fastened to it.

Next time when the movement of the slide 24 is reversed, the cam 26 will come against the tooth 18b At the moment of stopping, each time before the rotation of the bell is reversed by the drive 6, the mating parts 4 and 5 are separated then put in contact the slide 24 as well as the distance between the-cams 26 and 27 are set so that the turning angle of the bell would be larger in one direction than in the opposite direction. I

After the completion of as many cycles of reciprocating motion as there are the teeth 18 on the disc 17, the bell 5 makes a full revolution.

This ensures mutual contact between all the points of the lapped surfaces of both parts and improves the accuracy of the cross sectional shape of said surfaces.

Owing to the fact that the bell 5 is rigidly connected with the vertical shaft 11 whose upper end is installed in the cross member 3 and the lower end in the rod 9 of the drive 6, said bell does not change its position infixing one of the pa'rtsbeing lapped; a power drive for periodical separation of the parts being lapped; a vertical shaft one end of which is installed in said power drive; a disc with radially protruding elements, secured on said shaft and rigidly connected to the other part being lapped, and two synchronously operating reciprocating-rotary drive means arranged diametrically opposite to said disc and interacting with its radial elements to oscillate said disc and hence said other pan 7 2. A device according to claim 1, wherein the lower end of the vertical shaft is connected with the power drive for separating the parts being lapped, said drive serving as a support for said shaft.

3. A device according to claim 1, wherein the power drive for separating the surfaces being lapped is made in the form of a hydraulic cylinder consisting of a body, and a piston with a rod, the latter being provided with a screwed-on nut capable of moving axially along said rod to adjust the bottom-most portion of the piston.

4. A device according to claim 1, wherein the upper end of the verticalshaft is installed in a bearing located in across member which is mounted on two vertical columns. v

5. A device according to claim 4, wherein the vertical columns are movable transversely with relation to the shaft to suit the dimensions of the parts being lapped. I

6. A device according to claim 1, wherein the reciprocating-rotary drive means are each in the'form of a hydraulic cylinder whose body is rigidly connected to a guide while its piston rod is connected with a slide moving along said guide, said slide carrying twoaxlemounted spring-loaded cams which engage successively all the radial elements of said disc and wherein the guide mountsa rigidly installed stop engaging one of the cams and lowering it by rotating it around its axle at the end of the slide stroke to one of the sides.

4 it i i 

1. A device for lapping tapered mating surfaces of parts, mainly bells and cups for blast-furnace charging devices comprising: means for setting and immovably fixing one of the parts being lapped; a power drive for periodical separation of the parts being lapped; a vertical shaft one end of which is installed in said power drive; a disc with radially protruding elements, secured on said shaft and rigidly connected to the other part being lapped, and two synchronously operating reciprocatingrotary drive means arranged diametrically opposite to said disc and interacting with its radial elements to oscillate said disc and hence said other part.
 2. A device according to claim 1, wherein the lower end of the vertical shaft is connected with the power drive for separating the parts being lapped, said drive serving as a support for said shaft.
 3. A device according to claim 1, wherein the power drive for separating the surfaces being lapped is made in the form of a hydraulic cylinder consisting of a body, and a piston with a rod, the latter being provided with a screwed-on nut capable of moving axially along said rod to adjust the bottom-most portion of the piston.
 4. A device according to claim 1, wherein the upper end of the vertical shaft is installed in a bearing located in a cross member which is mounted on two vertical columns.
 5. A device according to claim 4, wherein the vertical columns are movable transversely with relation to the shaft to suit the dimensions of the parts being lapped.
 6. A device according to claim 1, wherein the reciprocating-rotary drive means are each in the form of a hydraulic cylinder whose body is rigidly connected to a guide while its piston rod is connected with a slide moving along said guide, said slide carrying two axle-mounted spring-loaded cams which engage successively all the radial elements of said disc and wherein the guide mounts a rigidly installed stop engaging one of the cams and lowering it by rotating it around its axle at the end of the slide stroke to one of the sides. 